1. Field of the Invention
The present invention relates generally to movie projection systems and, more specifically, to platter-type movie projection systems. The present invention is a plurality of selectively positionable magnetic plates having means for adhering said plates to a platter and a plurality of selectively removable/positionable magnetic keepers.
In addition the present invention provides for an additional element in the form of a stratum material for dissipating static charge that accumulates within the film media.
2. Description of the Prior Art
The most prevalent equipment used in multiplex movie theaters is a projector having a three-tier platter system which uses a first tier to feed film to the projector and a second tier to take up film from the projector and a third tier for loading new prints. The three-tier platter system is comprised of a stanchion having arms supporting large aluminum disks (platters) with each disk having a motor for independently rotating the disk.
When a movie theater receives a movie print, it comes in a plurality of shipping canisters each having about 18 minutes of film per shipping canister dependant on the type of film media. For economic reason, the movie industry moved from a triacetate film to polyethylene terephthalate commonly referred to as polyester film, which has superior strength and tear characteristics.
The film is removed from the shipping canisters and wound onto a single platter. Each canister end piece being spliced to the next canister beginning piece until all canisters have been wound onto a single platter.
In the center of each platter is a bore wherein is mounted a different device depending on the purpose of the platter. While the film is being loaded onto a platter, a compressible ring serves as a spool. When it is time to run the film, the collapsible ring is compressed, removed and another device consisting of a plurality of rollers having electrical connection to the platter motor is inserted into the bore. This device will control the rotation of the platter as the film is feed from the center of the platter to the projector and another motor controls the print take-up platter.
While this system has functioned well for many years the move from triacetate film to polyester film has developed a number of problems which plague movie houses.
The polyester film accumulates a static charge from the aluminum platter as it is being loaded onto the platter. Once the film is feed to the projector, the static charge between the layers of film causes the film to cling to itself resisting removal.
Included with the aforementioned roller assembly is a servo arm that has the film threaded therethrough and controls the platter rotation by causing platter rotation as the film tensions the servo arm. The point of separation of the film from the remaining film, which should be diametrically opposed to the servo arm, starts to lag behind its optimal release point until it binds and the movie is halted. Another problem with the polyester film is that it is almost half the thickness of triacetate film. As the movie nears the last half-hour, the platter is left with a large thin doughnut of film that has a tendency to oscillate as the platter is rotating and has been known to fall off the platter. Again abruptly ending the movie.
The industry has addressed this problem by attaching suction cups about the periphery of the film prior to running the film but these suction cups have been known to fall off from the rotating platter probably due to the pressure placed on them by the film.
Another method is to use a temporary adhesive to hold retaining members in place but this requires cleaning the platter between uses.
While these systems and devices may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.
Therefore it is felt that a need exists for the present invention which will eliminate the static charge of the polyester film by placing a static dissipating stratum to the aluminum platter. Furthermore, the circumference of the film can be fixed by cutting radial slots into the static dissipating stratum and placing a magnetic material therein whereby film retaining members having magnets, which will not adhere to the aluminum, encased therein that can be selectively positioned at the periphery of the film. The number of said radial slots can be as few as three and is a variable of personal preference.
The magnetic material can be permanently affixed to the aluminum platter or removably attached by any means known within the art such as adhesively.
The present invention is a stratum material for dissipating static charge that accumulates within the film media and a plurality of retaining members selectively positioned at the periphery of a spool of film. Said retaining members encasing magnetic elements that magnetically attach to a magnetic material which has been placed in a variable number of radial slots in the static dissipating stratum material.
A primary object of the present invention is to provide a film delivery and recovery system that will overcome the shortcomings of prior art devices.
Another object of the present invention is to provide a film delivery and recovery system having an anti-static stratum substantially covering the top surface of the platter.
Yet another object of the present invention is to provide a film delivery and recovery system having an anti-static stratum substantially covering the top surface of the platter having a plurality of radial slots cut therein.
Still yet another object of the present invention is to provide a film delivery and recovery system having an anti-static stratum substantially covering the top surface of the platter having a plurality of radial slots cut therein having a magnetic material positioned within said slots.
A further object of the present invention is to provide a film delivery and recovery system having an anti-static stratum substantially covering the top surface of the platter having a plurality of radial slots cut therein having a magnetic material positioned within said slots having retaining film members magnetically attached thereto.
A still further object of the present invention is to provide a film delivery and recovery system having magnetic film print retaining members which can be selectively attached or removed from said magnetic material.
Another object of the present invention is to provide a film delivery and recovery system having magnetic film print retaining members which can be selectively positioned at the periphery of the film print to keep the print from oscillating on the platter.
Additional objects of the present invention will appear as the description proceeds.
To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims.